Read the following research scenario:

Modern urban environments are increasingly designed to integrate green spaces, yet their actual impact on residents' mental health is still widely debated. Why do some individuals report a dramatic reduction in daily anxiety after visiting a park, while others experience no noticeable change? Does the size of the green space, or the distinction between active recreation (like jogging) and passive relaxation (like sitting by a pond), play a key role in stress relief? Perhaps working-age adults benefit differently compared to retirees. Many questions remain about how interaction with urban green spaces relates to psychological stress. To investigate this further, researchers plan to use a self-report questionnaire to explore the relationship between green space interaction and anxiety levels.